1
THE MIDDLE EAST DESALINATION RESEARCH CENTER
Sulnate of Oman ONEP (Morroco)
1- GEPEA, UMR CNRS 6144, France2- Chemistry dept., LACHIMIA, U. de Dakar, Senegal3- Veolia Water, Anjou Recherche, France4- ONEP, Morocco5- MEDRC, Muscat, Sulnate of Oman
INTENSIFICATION OF BRACKISH WATERS DESALINATION USING NANOFILTRATION (NF)
IN THE PLACE OF REVERSE OSMOSIS (RO)Case studies in Morocco and in Senegal
Maxime PONTIE1, Hanane DACH1,2, Pascal JAOUEN1, Courfia DIAWARA3, Jérôme LEPARC4,
Mohamed HAFSI4, Nourredine GHAFFOUR5
3rd Oxford Water and Membranes Research Event – September 12th - 15th 2010, Lady Margaret Hall, The University of Oxford (UK)
www.gepea.fr
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Objectives
Evaluate, at a pilot scale, the possibilities to produce drinking water by NANOFILTRATION (NF) from brackish groundwaters contaminated with F- ;
Compare the performances of NF vs reverse osmosis (RO)in terms of water productivity , membrane efficiencyvs salts rejection and energy consumption ;
Help to develop local « membrane » activities by research teams in MOROCCO and in SENEGAL.
3
0
10
20
30
40
1965 1975 1985 1995 2005
Introduction
Inta
lled
capa
city
(bill
ions
lite
rs/d
ay)
Years
(from Arabi M. A., “Desalination growth in the MENA r egion”Arab water world, sept.-oct. 2003 - 36 (5) 56)
51%
33%
8%4%
4%
RO
MSF
MED & VC
ED
NF
Installed capacity by process (IDA Desalination Yearbook, 2007)
Brackish waters desalination market in the world
Brackishwaters
ROEvaporation
4
0
1
2
3
4
5
6
7
8
9
10
0 5 10 15 20 25 30 35 40 45
Salinity (g/L)
Energy (kWh/m 3)
SWRO with ERI (Y=0.45)
SWRO (Y=0.45)
BWRO (y=0.7)
NF (Y=0.8)
Energy consumption in NF vs ROIntroduction
(F. VINCE, MEDRC Project N° 04-As-005, report 4, Dec. 06)
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Interest of NF vs RO
• Selectivity between ions
• Low applied pressure
• Low energy consumption
• High recovery (> 70%)
• Similar simplicity of the technology
• Very well adapted for brackish water
Introduction
6(M. Pontié, C. K. Diawara, M. Rumeau, Desalination 15 l (2002) 267-274)
32535,5Cl-
104796SO42-
274127I-161540Ca2+
45423Na+
36339K+
IEhyd I (kJ.mol-1)M (g.mol-1)Ion
F- 19 449
SO42-
F-
Cl-
Br -
I -
Rej
e cti
on(%
)
R (SO42-) > R(F-) > R(Cl-) > R(I-)
BW30
NO SELECTIVITY IN RO
Introduction RO membrane selectivity
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NF90
(M. Pontié, C. K. Diawara, M. Rumeau, Desalination 15 l(2002) 267-274)
R(F-) > R(Cl-) > R(I-)
R(F-) >> R(I-) >R(Cl-)
GOOD SELECTIVITY IN NFBETWEEN MONOVALENT SODIUM SALTS
Introduction NF selectivity between monovalents ions
8
65
70
75
80
85
90
95
0 2 4 6 8 10 12 14
Rej
ectio
n (%
)
Transmembrane pressure (bar)
F -
Cl--
I-
NF45
(A. Lhassani, M. Rumeau, D. Benjelloun, M. Pontié,Wat. Research , 35 (13) (2001) 3264-)
Selectivity for a F-/Cl-/I - in a ternary mixture
Introduction
GOOD SELECTIVITY IN NFDEPENDING ON THE TRANS-MEMBRANE PRESSURE
NF selectivity between monovalents ions
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CORRELATION BETWEENSOIL PHOSPHATE CONTENT
Fatick
AND
WATER RESSOURCES RICH IN FLUORIDE IONS
- Fatick, Senegal- Khouribga, Morocco Eocene limit
F- isolinesF- < 0.1mg/L
Introduction
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DENTALFLUOROSIS(F- > 2 mg/L)
10 years of exposure to
4 mg/L F-, in Fatick,
SENEGAL
Regulation in drinking water : < 1.5 mg/L (WHO, 2006)
Introduction
11
OSSEOUSFLUOROSIS(F- > 4 mg/L)
15 years of exposure to 6-10mg/L F-, (Fatick, Senegal)
(TRAVI Y. Geological Sciences, (1993), mémoire 95, ISSN 0302-2684)
Introduction
12
Processes of water defluoridationIntroduction
13
Experimental Waters Characteristics
*Tan Tan water was doped with NaF at 5, 10 and 15 ppm
< 200-595Na+ (ppm)
< 5001040Hardness (°F)
< 20053500SO42- (ppm)
< 1.53.6 -13.51.1*F- (ppm)
< 50<220NO3- (ppm)
< 2506721200 - 1349Cl- (ppm)
< 100014003300 - 4000TDS (ppm)
6.5-98.227.9pH
< 2516.427T (°C)
WHO water
regulations
(2008)
Senegal
(Fatick,
Thiadiaye)
Tan Tan*Feed water
parameters
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(1) Feed water tank 2.6 m3 , Max feed flow of 3 m3/h ; (2) Pilot units(3) Water cooling unit (T=21°C)
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3
3
2
1
Experimental Description of the pilot units
Osmonics unit for lab scale experiments
Tan Tan pilot scale experiments
Thiadiaye unit (Senegal, 2010)
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Experimental
Operating conditions
�Flow rate ratio (Y) from 10 to 90%
� Permeate flux : 26 L.m-2.h-1
Membranes tested
�Membranes : 2NF (NF90, NF270) and 1RO (BW30)(supplier : DOW, Filmtec)
� Type : Thin Film Composite in polyamide
� Module : Spiral wound module (4” )
� Membrane area : 137 cm2, 7.6 m2 and
1380 m2 (Thiadiaye)
Structure of a Thin-Film Composite membrane
40 µm
120µm
0.2- 3 µm
Ultrathinbarrier layer
in polyamide
Microporouspolysulfone
Polyester support
Spiral wound module,
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Results and discussion Hydraulic permeability
Effect of the applied pressure on Tan Tan water
flux for the NF90 and BW30 membranes
(pH = 7.9, T = 21°C)
• Lp’ NF > Lp’ RO
• Pc RO ~ Pc NF
Jv=Lp’(∆P – σ∆Π)
Pc
0
10
20
30
40
50
60
70
80
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Jv (L
.h-1.m
-2)
Pressure (bar)
NF90
BW30
Πth. = 3.3 bar Transmembrane pressure (bar)
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TDS rejectionResults and discussion
• NF90 permits to test the highest flow yield (>70%)
with the lowest pressure
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10% 45% 70% 90%
0
2
4
6
8
10
12
14
16
18
20
22
BW30NF90
10%
45%
70%
90%
Feed
Pre
ssu
re (
ba
r)
Energy consumption
Required pressures for
desalination of Tan Tan water for the NF and
LPRO membranes studied at different
recovery rates (Y=70%,
permeate flux=26 L.m-2.hr-1)
nd
Results and discussion
36
100.
.r
PE
η∆=
BW30NF90
•∆P BW30 >> ∆P NF90
• Energy consumption is 2 times lower in NF
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OPERATING CONDITIONS : Membrane NF70 (Filmtec); T=26°C; Transmembrane pressure = 5-6 bar; Flow yield 10 %
Total Salinity (g/L) Hardness (°) pH Sulfate (mg/L) F- (mg/L) Chloride (mg/L)
Raw water 2.0 4.55 8.35 16.2 13.5 655
NF water 0.23 0 7.95 2.9 0.7 85
WHO 0.1< <0.5 - 6.5-9.5 < 250 0.8< < 1.5 < 250
(A. Lhassani, M. Rumeau, D. Benjelloun, M. Pontié, Water Res.35 (13) (2001) 3260–)
R (%) 88 100 - 82 95 87
Fluoride removal 1Results and discussion
KEY RESULTS IN SENEGAL - 1993
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Fatick Gandiaye Thiadiaye Kaolack GossasRobinet Puits1 Puits2 Puits1 Puits2 Robinet Puits Robinet Puits Robinet Puits
Temperature(°C)
16.4 13,2 13,8 10,9 15,9 18,5 17,0 20,0 19,2 20,9 20,5
Turbidity (NTU)
0.94 0,35 0,47 0,35 0,57 0,85 3,88 1,23 0,21 0,45 0,19
Nitrate (mg/L) <2 23,2 339 15,2 59,1 <0,4 129 <0,4 44,3 <0,4 27,1
TOC (mg/L) 7.07 1,12 1,84 4,25 1,74 2,55 1,77 1,40 0,69 1,83 1,10
TIC (mg/L) 65.66 3,94 5,03 14,35 7,34 58,83 39,81 57,92 6,42 55,65 21,2
Fouling index 3pH 8.22 7,03 6,89 7,78 7,63 8,33 8,38 8,25 7,79 8,67 7,97
Conductivity
(µs/cm)2820 211 1351 300 303 1715 772 1980 1198 2100 402
TH (°F) 3.0 3,4 28,4 8,6 6,0 34,0 29,0 2,8 19,2 3,4 12,0
TH Ca2+ (°F) 3.0 3,2 19,2 7,2 4,2 14,4 24,6 2,8 13,6 2,2 9,2
TAC (°F) 39 1,2 0,6 6,2 2,2 33,6 17,0 32,4 2,6 32,8 18,6
Fluoride(mg/L)
3.59 <0,1 0,259 <0,1 <0,1 4,45 0,224 2,6 <0,1 2,530,256
Chloride(mg/L)
672 41,9 213 41,17 42,4 291 68 403 328 444 51,7
Sulfate (mg/L) 53.0 4,6 30 3,9 1,1 122 7,1 66 7,9 60 8,5
UV254(mat.org)
0.238 0,032 0,192 0,726 0,078 0,092 0,218 0,161 0,020 0,066 0,015
UV436(couleur)
0.027 0,003 0,006 0,182 0,009 0,016 0,052 0,035 0,002 0,009 0,001
0
0,5
1
1,5
2
2,5
3
3,5
0 2 4 6 8 10
NF90NF270
Time (h.)
BW30
0
0.5
1
1.5
2
2.5
3
3.5
0 2 4 6 8 10
NF90NF270BW30
F- in the permeate(mg/L)
Operating conditionsP=7 barsFlow yield = 75%
0.8 mg/L
Fluoride removal 2Results and discussion
KEY RESULTS IN SENEGAL - 2004
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y = 0.009x + 0.001
R2 = 0.98
y = 0.025x + 0.038
R2 = 0.98
y = 0.863x + 0.0008
R2 = 0.99
0
0,05
0,1
0,15
0,2
0 0,5 1 1,5 2 2,5
1/Jv(h/L)
Cp(
g/L)
NF90
NF270
BW30
Results and discussion
Permeateconcentration (Cp) of NaCl vs 1/Jv
( membranes NF270, NF90 et OI, C= 0,001 M, T°=25°C,
pH=6.7, Y=5%)
1/Jv (h.L-1)
Cp
(g.L
-1)
BW30 Pure Diffusion
NF90 Diffusion >>> Convection
NF270 Convection >>> Diffusion
Cconv..
Mass tranfer in NF/RO
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Processes of water defluoridationIntroduction
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Variations of fluoride concentration in the permeate for the studied membranes with F- concentrations variations in Tan Tan
water (Y= 70%,Permeate Flux = 26 LMH)
Fluoride removal
(H. DACH, Ph Thesis, MEDRC Project 04As003 )
Results and discussion
0
0,2
0,4
0,6
0,8
1 5 10 15
NF90
BW30
[F- ] feed (mg/L)
[F- ] permeate(mg/L)
KEY RESULTS IN MOROCCO - 2008
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Paramètres Feed WHO after NF
Fluoride (ppm) 4.67 < 1,5
Sodium (ppm) 235 < 200
Chloride (ppm) 280 < 200
Magnesium
(ppm)
51 10 à 50
Calcium (ppm) 56 20 à 270
1.1
150
110
10
10
Feed flow 50 m3/h
Flow yield 70%
Modules
/ membrane area
36 (24+12)
/ 1338 m²
Step 2
Membrane NF 90-400
Thiadiaye Unit (Senegal)Results and discussion
THE FIRST DEFLUORIDATION UNIT IN THE WORLD – 2010
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Less fluorides in drinking water,
better health and dignity
recovering !
Thiadiaye, january 2010
THE FIRST DEFLUORIDATION UNIT IN THE WORLD – 2010
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Conclusion
We have shown for the first time, from lab scale to full scale,the main interest in NF vsRO for drinking water defluoridation
The best membrane is the NF90, due to :- higher water productivity (3 x)- lower specific energy consumption (2 x)- higher selectivity of monovalent ions, i.e. F- vsCl-- partition-diffusion mass transfer predominant
Through this collaboration 2 research teams dedicated to membrane technology started in Fes (Morocco) and Dakar (Senegal) and the first defluoridation unit using NF was builtrecently in Senegal (Thiadiaye).
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Acknowledgements�MEDRC: Projet n° 04-AS-005 (Sultanate of Oman)
� Fes University, LCA (Morocco), A. Lhassani
� VEOLIA WATER, (France), H. BUISSON and H. SUTY
�ONEP (Morocco)
�M. RUMEAU (France) initiator of the research topic
in 1992 (Senegal/France)
� Suez-Environment,CIRSEE, JM Lainé, France
MEDRC Project TEAM, Project n°04-AS-005
Thiadiaye, sept. 2009
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Ra = 13± 5 nm
NF270
Ra = 298± 10 nm
NF90
Results and discussion +NF/RO surface roughness
Ra = 125± 25 nm
BW30